A cryostat nozzle and a method of using a cryostat

摘要

A method of using a cryostat comprises supplying a stream of cold cryogas over a specimen, and surrounding said stream in the vicinity of the specimen by a dry annular flow of the same cryogas at ambient temperature. A nozzle for the cryostat comprises a central feed tube (36) for supplying the stream of cold cryogas over a specimen (35), and an annular feed opening (34) for supplying the dry annular flow of the same cryogas at ambient temperature.